Year	% of total primary
1971	13.580249786377
1972	15.4646396636963
1973	15.5345296859741
1974	14.4843597412109
1975	18.5227394104004
1982	17.4970302581787
1983	18.3929901123047
1984	19.2057590484619
1985	21.3725490570068
1986	17.5882701873779
1987	17.6779308319092
1988	17.4707794189453
1989	17.1040000915527
1990	16.3517608642578
1992	17.0598697662354